JPH0539916Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

This invention relates to a writing instrument that combines the knob structure of, for example, a knob-type sharp pencil and an eraser delivery mechanism.

[Conventional technology]

In conventional knock-type sharp pencils, in which the rear cap is connected to the rear end side of the outer cylinder with a tip so that it can move in the axial direction, the core pipe is axially moved inside the outer cylinder and the rear cap. An eraser caulked with a metal ring is removably fitted and held at the rear end of this core pipe, and the rear cap is clicked through this eraser, thereby opening the core pipe. Corresponding axial response leads to lead feeding and the eraser can be used by removing the eraser cap from the rear cap.

[Problem that the invention attempts to solve]

In such conventional sharp pencils, the entire relatively long rear cap, which is a coaxial extension of the outer cylinder, must be moved in a knocking motion when feeding the lead.
For this reason, there was a problem in that the rear cap got caught in the hand gripping the outer cylinder when it was knocked, making it difficult to knock. In addition, because the eraser is always held and fixed in a fixed position, the protrusion length from the caulking metal ring is short due to the strength of the eraser itself, and the amount of extension cannot be adjusted depending on the degree of wear, so the wear rate is low. There was a problem that the system became unusable very quickly. Therefore, the present applicant filed an earlier application filed in 1983-
The above-mentioned problems were solved with the writing instrument No. 158220. In the writing instrument of this earlier application, when the rear cap connected to the rear end of the outer cylinder is rotated, the eraser is sent out by a screw feeding action, and is slidably inserted into the rear cap in the axial direction, and the eraser is inserted outward from the rear end. The core is fed by knocking a knock cap extending from the top. However, in the case of the writing instrument of the earlier application, there was a problem in that when the eraser was sent out by rotating the rear cap after the notch cap was clicked, the notch cap would move with it. However, if the friction between the eraser and the notch cap is stronger than that of the locking rib, the problem remains that the notch cap may move, resulting in a lack of reliability during mass production. Therefore, this invention was devised to solve the above problems, and in addition to the effects of the previous application, it is possible to hold the notch cap in a constant rearward protruding position when not knocking, and to ensure the movement of the notch cap when feeding out the eraser. The purpose is to provide a writing instrument that can prevent

[Means to solve the problem]

The writing instrument of this invention has a lead pipe that pushes out the lead stored inside by pushing the reed chuck toward the distal end in the axial direction, and a core pipe that is freely movable in the axial direction. an outer cylinder to be housed in the lead chuck, an elastic body for tightening the lead chuck by urging the core pipe rearward, a rear cap rotatably connected to the rear end of the outer cylinder, and a rear cap rotatably connected to the rear end of the outer cylinder; a lock cap which is provided within the cap so as to be movable in the axial direction with movement in the axial direction being restricted, and whose rear end side protrudes from the rear end of the rear cap;
Inside this lock cap, it is provided so as to be movable in the axial direction, with movement in the axial direction being restricted.
It has an eraser holder that holds the eraser at the rear end, and a screw shaft that is inserted into the eraser holder from the tip side and moves the eraser holder in the axial direction,
The distal end of the threaded shaft is connected to the rear end of the outer cylinder so that it can move freely in the axial direction with movement in the axial direction restricted, and the rear end of the core pipe and the distal end of the threaded shaft are connected to each other. A feed screw member is provided to create a play of a predetermined distance between the feed screw members, and this feed screw member is biased backward to abut against the tip of the knock cap, and when the knock cap is not knocked, the feed screw member is provided with a play of a predetermined distance. The device is characterized by comprising an elastic body that creates the distance between the screw shaft portion and the tip of the screw shaft portion.

[Effect]

In this invention, when the knock cap is knocked, the feed screw member moves forward together with the knock cap, and the core pipe is pushed forward by the feed screw member, thereby performing core feeding. When the knob is released, the knob cap is moved backward by the biasing force of the elastic body and is held at a constant rearward protruding position. On the other hand, when the rear cap is rotated in the forward direction, the eraser holder is rotated in the forward direction together with the rear cap, and the eraser holder is screwed in the axial direction by the feed screw member and moved backward, so that the eraser is placed behind the notch cap. It is rolled out from the edge. Further, when the rear cap is rotated in the reverse direction, the eraser holder is moved backward in the axial direction by the feed screw member via the knob cap which rotates together with the rear cap, and the eraser is retracted into the knob cap. I am made to do so. Therefore, by rotating the rear cap in the forward and reverse directions, the amount of the eraser that is fed out can be adjusted according to the level of wear. Furthermore, when the knob is released, the above-mentioned knock cap is moved backward by an elastic body and held at a constant rearward protruding position. Therefore, there is no risk that the notch cap will be moved when the eraser is fed out.

【Example】

An embodiment of this invention will be described below based on the drawings. In the hook-type sharp pencil shown in FIG. 1, a tip 2 is removably connected to the tip of an outer cylinder 1 by screwing or the like. A lead delivery mechanism 3 is built into the tip 2, and the tip of a lead pipe 4 is connected to this lead delivery mechanism 3. As a result, the lead delivery mechanism 3 and the lead pipe 4 are integrated into a unit with respect to the tip 2. In the middle of the inner peripheral surface of the outer cylinder 1, a core pipe holding part 1a having a small diameter step annular shape is coaxially provided. This core pipe holding part 1a holds the core pipe 4 remaining inserted in the outer cylinder 1 so as to be slidable in the axial direction on the same axis when the rear cap 7 is removed, which will be described later. 4 is prevented from tilting. The lead delivery mechanism 3 includes a tip pipe 30 that protrudes and retracts from the tip of the tip tool 2, a friction applying member 31 that applies a frictional engagement force to the lead S sent out through the tip pipe 30, and a friction imparting member 31 that applies a frictional engagement force to the lead S sent out through the tip pipe 30. A lead chuck 32 connected to the tip of the lead chuck 32, a chuck tightening ring 33 for tightening the lead chuck 32, and a lead chuck 32 that is slidably inserted in the rear side of the tip tool 2 in the axial direction, and the front end is connected to the rear of the chuck tightening ring 33. A cushion sleeve 34 is brought into contact with the end, and a chuck tightener that urges the chuck tightening ring 33 in the forward direction and urges the lead chuck 32 together with the core pipe 4 in the backward direction through the cushion sleeve 34. It consists of an elastic body 35 for attachment. Therefore, by connecting the tip 2 at the tip of the outer cylinder 1, the core pipe 4 unitary to the tip 2 is inserted into the outer cylinder 1 so as to be slidable in the axial direction. In this state, the rear end of the core pipe 4 extends from the rear end of the outer cylinder 1. A cap 5 is removably fitted onto the rear end of the core pipe 4 to prevent the core S stored therein from spilling out. The cap 5 is made of, for example, an extremely thin cylindrical body plated with chrome. The ultra-thin cylindrical cap 5 has a net protrusion length from the rear end of the core pipe 4 only by the ultra-thin wall thickness at its rear end, and this protrusion length is proportional to the overall length of the writing instrument. Since this can be almost ignored, the overall length of the writing instrument can be shortened. Furthermore, if the rear cap 7, which is removably connected to the rear end of the core pipe 4 via the intermediate ring 6, is removed, the entire cap 5 will be exposed, and the entire portion will become a pinching area. 5 can be easily removed, and the core pipe 4 can be easily refilled with the core. The intermediate ring 6 is composed of an outer flange 6a provided at the middle part of its outer periphery, and a front cylindrical part 6b and a rear cylindrical part 6c bordered by the outer flange 6a. The rear end side of the connector 8 is previously connected to the front end side of the rear cap 7 by being screwed into the inside of the front end side of the rear cap 7. That is, as shown in FIGS. 1 to 5, the connector 8 is integrally formed into a stepped cylindrical shape whose diameter gradually increases from the front end toward the rear end.
Front cylinder part 80, middle cylinder part 81, and rear cylinder part 82
It is made up of. In this connector 8, the outer circumferential surface of the middle cylindrical portion 81 is provided with an engagement recess 1b (see FIG. 1) provided on the inner circumferential surface on the rear end side of the outer tube 1 for fitting and engaging. Protrusion 83 (Figs. 1 to 5, 7
(see figure) is integrally protruded. Further, the engaging protrusion 83 of the middle cylindrical portion 81 is provided with one or more slits 84 in the axial direction. Here, the engaging protrusion 83 and the slit 84 are provided on a right-angled cross-sectional line of the middle cylindrical portion 81. The middle ring 6 is rotatably fitted into the middle cylindrical portion 81 as shown in the first figure. At this time of fitting, the intermediate cylindrical portion 81 is bent in the diametrical direction by the slit 84, so that the intermediate ring 6 can be easily fitted. By screwing the rear end cylindrical portion 6c of the intermediate ring 6 into the front end side of the rear cap 7, the rear end side of the connector 8 is coaxially connected to the front end side of the rear cap 7. . As a result, the intermediate ring 6 and the connector 8 are integrated into a unit on the front end side of the rear cap 7. While inserting the rear end side of the core pipe 4 into the outer cylinder 1 into the connector 8, fit the connector 8 into the rear side of the outer cylinder 1 from the front cylinder part 80 side,
Moreover, the intermediate ring 6 is provided inside the rear end of the outer cylinder 1.
By fitting the front cylinder part 6b of the outer cylinder 1
and the rear cap 7 are coaxially and rotatably connected. Here, the intermediate ring 6 is rotatable relative to the outer cylinder 1 and the connector 8, and is integrally connected to the rear cap 7 by screws. Therefore, the outer cylinder 1 and the rear cap 7 are coaxially and rotatably connected as described above. In this connected state, the rear end side of the core pipe 4 protrudes rearward from the rear end of the connector 8, so that the core pipe 4 can be knocked through the cap 5 with a knock shaft 93, which will be described later. It's summery. Furthermore, in the connected state, the connector 8 is engaged in the outer cylinder 1 in the axial direction. As the engagement means, the outer circumferential surface of the front cylinder part 80 and the inner circumferential surface on the rear end side of the outer cylinder 1 are arranged as shown in FIGS. 2 and 3.
As shown in the figures and the sixth figure, each of them is formed to have an octagonal cross section and are fitted and engaged with each other. Note that these shapes may be other polygonal shapes. Furthermore, the engaging projection 83 of the middle cylindrical portion 81 of the connector 8 is fitted and engaged with the engaging recess 1b (see FIGS. 1 and 7) of the outer cylinder 1. When the connector 8 is fitted, that is, when the connector 8 is inserted into the outer cylinder 1, the connector 8 is elastically deformed in the diametrical direction by the slit 84, so that the connector 8 is inserted and the engagement is performed. The projection 83 can be easily fitted into the engagement recess 1b. Furthermore, as described above, since the outer cylinder 1 and the connector 8 are engaged with each other in the axial direction in two stages, sufficient fitting force between them can be obtained. This prevents the outer cylinder 1 and the rear cap 7 from being rotated more than necessary. Incidentally, since the above-mentioned fitting force can be sufficiently obtained only by the engagement between the above-mentioned engagement protrusion 83 and the above-mentioned engagement recess 1b, the outer circumferential surface of the above-mentioned front stage cylinder part 80 and the inner circumferential surface of the above-mentioned outer cylinder 1 do not necessarily have a cross section 8. It is not necessary to form it into a square shape. Further, the engaging protrusion 83 may be formed to be long in the axial direction of the outer peripheral surface of the middle cylinder part 81, as shown by the two-dot chain line in FIG.
The engagement recess 1b is not formed in the case, and the engagement protrusion 83 is pressed into engagement with the inner circumferential surface of the outer cylinder 1 by utilizing the deflection in the diameter reduction direction of the slit 84 of the middle cylinder part 81. By doing so, it is possible to obtain a sufficient fitting force between both of them, and it is also possible to omit the molding of the above-mentioned engaging recess 1b, and there is no need to perform forced punching on the mold, thereby reducing the burden on the mold. There is no. As shown in FIGS. 1, 2, 5, and 8, an axial sliding groove 85 is provided at a position symmetrical to the peripheral wall of the rear cylindrical portion 82 of the connector 8. As shown in FIGS. This axial sliding groove 85 is formed by fitting and engaging a front end locking protrusion 94 of the feed screw member 9, which will be described later, so as to be able to slide in the axial direction, thereby engaging the feed screw member 9 in the axial direction. It is. Incidentally, the engagement means is not limited to the above-mentioned axial sliding groove 85,
Any means may be used as long as it can engage the front end locking protrusion 94 of the feed screw member 9 in the axial direction within the rear cylindrical portion 82 of the connector 8. As shown in the first figure, the front end side of the feed screw member 9 is connected to the rear stage cylindrical portion 82 so as to be slidable in the axial direction. The feed screw member 9 includes a screw shaft portion 90 for feeding out the eraser, and a front end of the screw shaft portion 90 that is coaxially connected to the front end of the screw shaft portion 90 via a circular flange-shaped stopper step portion 91. 92, which is formed into a two-part cylindrical shape that can be expanded and contracted in the radial direction, and a front end locking protrusion 94 that is integrally provided on the outer peripheral surface of the front end of this connection shaft part 93. ing. The feed screw member 9 is configured such that the connecting shaft portion 93 thereof is contracted in the radial direction and the rear cylindrical portion 82 of the connector 8 is
The front end locking protrusion 94 is fitted into and engaged with the axial sliding groove 85 of the rear cylinder part 82 by the elastic restoring force of the connecting shaft part 93. The feed screw member 9 is connected to the stopper stepped portion 91 at the rear end of the connecting shaft portion 93 and the connector 8.
It is biased in the backward direction by the elastic body 10 interposed between it and the rear end of the rear stage cylindrical part 82. Thereby, the feed screw member 9 is connected to the rear end of the connector 8 so as to be slidable in the axial direction, and both of them are integrated into a unit. Here, a distance a is provided between the rear end of the core pipe cap 5 and the tip of the connecting shaft portion 93. This distance a is the cushion stroke in the cushion mechanism of the lead S, and even in normal knot-type writing instruments that do not have a cushion mechanism, due to the variation in the overall length, the distance a or a slight distance
Time is essential. That is, when the distance a disappears, the head of the lead pipe cap 5 comes into contact with the connecting shaft part 93 and is in a just-knocked state, which causes the lead to slip during writing, making it completely useless as a writing instrument. Become. Further, a distance b is provided between the rear end of the core pipe cap 5 and the rear end of the connector 8. This distance b is determined by the fact that the feed screw member 9 moves forward at the rear end notch, which will be described later, and the rear end of the core pipe 4 is pushed through the cap 5 at the tip of the connecting shaft portion 93, and the core pipe 4 moves forward. This is the notch distance at which the lead S is sent out from the tip pipe 30 by moving forward. The screw shaft portion 90 of the feed screw member 9 is inserted into and engaged with the eraser holder 11 having a penetrating cylindrical shape so as to be movable in the axial direction. This eraser holder 11 is attached to the rear cap 7.
The lock cap 12 is inserted into the lock cap 12 so as to be slidable in the axial direction, and engaged in the axial direction. As an engaging means, an outward engaging claw 11a integrally protrudes from the outer peripheral surface of the front end side of the eraser holder 11.
However, the guide groove 1 provided in the above-mentioned knock cap 12
2a is fitted and engaged. Here, on the front end side of the knock cap 12, as shown in FIGS. 9 and 17, a cut slit 12b along the axial direction is formed in the guide groove 12a.
It is located on a cross-sectional line perpendicular to the Therefore, when the outward engaging pawl 11a is fitted into the guide groove 12a, the knock cap 12 is elastically deformed in the diametrical direction at the cut slit 12b, so that the fitting can be easily performed. After the fitting, the cut slit 12b elastically restores in the diametrical direction, thereby connecting the outward engaging claw 11a and the guide groove 12a.
are securely fitted and engaged. Incidentally, the cut slit 12b of the above-mentioned knock cap 12 is formed as shown in FIGS. 15 and 16.
It may be replaced with a cut slit 11d provided in the axial direction of the front end side of the eraser holder 11 and located on a cross-sectional line perpendicular to the outward engaging claw 11a and the inward engaging claw 11b of the eraser holder 11. Even in this cut slit 11d, in order to facilitate the elastic deformation of the eraser holder 11 in the radial direction, the cut slit 11 of the notch cap 12 is
2b, the outward engaging claw 11a can be easily fitted into the guide groove 12a, and the fitting engagement can be performed reliably. Further, an inwardly engaging claw 11b is integrally provided on the inner circumferential surface of the front end side of the eraser holder 11, and this inwardly engaging claw 11b is fitted into the threaded groove 95 of the screw shaft portion 90 so that the screw can be fed. are combined. Thereby, the eraser holder 11 is connected to the feed screw member 9 so as to be screwable. Here, when the front end of the eraser holder 11 comes into contact with the stopper step 91 of the screw shaft 90, the pitch is set to 0 for several degrees on the outer periphery of the front end 95a of the screw groove 95. . Therefore, even if the eraser holder 11 is forcibly turned in the engagement direction in a state in which the inward engaging claw 11b is engaged with the front end 95a of the thread groove 95, the stopper has sufficient strength to cope with the forcible rotation. This prevents the inward engaging claw 11b from biting into the front end 95a of the threaded groove 95. Further, inside the rear end side of the eraser holder 11, a large diameter step-shaped eraser fitting hole 11c is provided, and the base of the eraser 13 is removably fitted and supported in the fitting hole 11c. ing. Furthermore, a rib having a triangular cross section, for example, is provided on the inner circumferential surface of the fitting hole 11c, and this rib is bitten into the eraser 13 to prevent the eraser 13 from coming loose. You can. In addition, as a means for preventing it from coming off, as shown in Figure 18, an insertion needle 14 is integrally formed at the center of the rear end of the eraser holder 10 or is attached as a separate part, and the eraser 13 is inserted into the insertion needle 14 and supported. You may let them. In this case, the eraser fitting hole 11c shown in FIGS. 1 and 13 can be omitted, thereby securing space and making it possible to load a thicker eraser, making it extremely convenient to use. gets better. On the other hand, the knock cap 12 is engaged in the rear cap 7 in the axial direction. As the engaging means, as shown in the first figure, a locking protrusion 12c integrally protruding from the outer peripheral surface of the lock cap 12 is inserted into an axial engaging groove 7a provided on the inner peripheral surface of the rear cap 7. They are engaged so that they can slide in the direction. The engaging projection 12c may be integrally provided on the inner peripheral surface of the rear cap 7, and the axial engaging groove 7a may be provided on the outer peripheral surface of the knock cap 12 to form the engaging means. A clip 15 is attached to the rear cap 7.
is installed. Here, a raised wall part 7b for attaching a clip is integrally formed on the rear outer peripheral surface of the rear cap 7, as shown in FIGS. 1 and 10 to 12. An insertion groove 7c is provided. The inside of this clip insertion groove 7c is open into the rear cap 7. The clip insertion groove 7c is a molded groove integrally formed with a molded pin during molding of the rear cap 7, and the clip 15 is attached using this molded groove. The base end side of this clip 15 has an insertion piece portion 15a.
is folded back into a substantially U-shape, and a locking piece 15b that is further bent inward at a substantially right angle is provided at the tip of the insertion piece 15a. Then, the insertion piece 15a is press-fitted into the clip insertion groove 7c, whereby the base of the clip 15 is inserted into the raised wall 7 of the rear cap 7.
It is attached to b. In this attached state, the insertion piece 15a of the clip 15 is pressed into engagement with the clip insertion groove 7c, and the locking piece 15b is inserted into the rear cap 7 through the clip insertion groove 7c. It protrudes and comes into sliding contact with the outer peripheral surface of the knock cap 12. Here, the knock cap 12 has a stopper stepped portion 91 of the screw shaft portion 90 that is in pressure contact with the front end thereof.
The rear end of the locking protrusion 12c of the lock cap 12 is locked to the front end of the locking piece 15b of the clip 15 by being biased in the backward direction by the elastic body 10 via the lock cap 12. Therefore, the locking piece 15b of the clip 15
This restricts the backward movement of the knock cap 12, prevents the knock cap 12 from slipping out, and holds the knock cap 12 at a constant rearward protruding position when the knock cap is not knocked. In this way, clip 15 is connected to lock cap 1.
By preventing the cap 2 from coming off, there is no need to provide a top screw or the like at the rear end of the rear cap 7 to prevent the cap from coming out, which reduces the number of parts.
The defective rate of writing instrument products is reduced and costs can be reduced. Further, the clip 15 has an insertion piece portion 15
It is only necessary to insert the clip (a) into the clip insertion groove 7c, and therefore assembly is easy. Further, since the elastic body 10 only needs to bias the knock cap 12 in the backward direction, it is sufficient that the elastic body 10 has a weak elastic force. Next, when assembling the writing instrument, the tip 2, in which the lead delivery mechanism 3 and the lead pipe 4 are integrated, is screwed onto the tip of the outer cylinder 1 and connected. On the other hand, when the outward engaging claw 11a of the eraser holder 11 is pushed into the above-mentioned knob cap 12 from the front end direction of the knob cap 12 in alignment with the guide groove 12a, the cut slit 12b of the knob cap 12 or the cut slit 11d of the eraser holder 11 is pushed. is elastically deformed in the diametrical direction,
The outward engaging claw 11a is easily fitted into the guide groove 12a from the inside, and after the fitting, the cut slit 12c or 11d is elastically restored in the radial direction, whereby the outward engaging claw 11a
The engagement between the guide groove 12a and the guide groove 12a is ensured. Next, after inserting the above-mentioned knock cap 12 into the rear cap 7 from its rear end, the insertion piece 15a of the clip 15 is press-fitted into the clip insertion groove 7c of the rear cap 7. Thereafter, the front end locking protrusion 94 integrally provided on the outer peripheral surface of the front end of the connecting shaft portion 93 is aligned with the axial sliding groove 85 of the connector 8, and elastic deformation is performed in the diametrical direction using the cut slit 92. , the rear cylinder part 6c of the intermediate ring 6 is fitted into the axial sliding groove 85 and connected to the intermediate cylinder part 81 of the connector 8.
Insert. The feed screw member 9 of these units, which uses the connector 8 as a base, is screwed into the eraser holder 11. Then, by screwing the rear cylindrical portion 6c of the intermediate ring 6 inserted into the connector 8 into the inside of the front end side of the rear cap 7, each is integrally formed into a unit. Therefore, while inserting the rear end side of the core pipe 4 extending from the rear end of the outer cylinder 1 into the front cylinder part 80 of the connector 8 protruding from the tip of the rear cap 7, By fitting the front cylindrical portion 6b of the intermediate ring 6 into the rear end side, the outer cylinder 1 and the rear cap 7 are rotatably connected, completing the assembly of the writing instrument. Therefore, when the rear cap 7 is removed from the outer cylinder 1, the cap 5 at the rear end of the core pipe 4 is exposed, and by removing this cap 5, the core pipe 4 can be easily refilled with the core S. It can be carried out. Next, the operation will be explained. Rear cap 7
When the rear cap 7 is rotated in one direction with the eraser 13 retracted inside, the eraser holder 11 rotates together with it via the knob cap 12, causing the eraser holder 11 to engage inward. The claw 11b is guided by the thread groove 95 of the feed screw member 9, and the eraser holder 11 moves backward within the knock cap 12. As a result, the eraser 13 is sent out from the rear end of the notch cap 12 and is used for erasing characters. From this state, when the rear cap 7 is rotated in the opposite direction, the eraser holder 11 rotates together with the rear cap 7, and its inward engaging claw 11b is inserted into the screw groove 95.
By moving forward while being guided by the eraser 13, the eraser 13 retracts into the knock cap 12. In either state in which the eraser 13 is protruded or retracted in this manner, when the knock cap 12 is knocked, the feed screw member 9 is moved through the stopper step 91 that is engaged with the tip of the knock cap 12. Move forward. As the lead pipe 4 is pushed forward through the cap 5 by the front end of the threaded shaft portion 90 of the feed screw member 9, the lead delivery mechanism 3 operates to sequentially deliver the tip pipe 30 and the lead S. When the knock cap 12 is released, the knock cap 12 is moved backward by the urging force of the elastic body 10, and the locking protrusion 1 of the knock cap 12 is engaged with the locking piece 15b of the clip 15.
2c, the knob cap 12 is held in a constant rearward projecting position.

[Effect of the idea]

As described above, according to this invention, by knocking the knock cap which protrudes from the rear end of the rear cap which is rotatably connected to the rear end of the outer cylinder, the lead can be fed smoothly, and by rotating the knock cap, the eraser can be made to appear and disappear from the rear end of the knock cap. As a result, the eraser can be advanced according to its degree of wear and the amount of advancement can be appropriately adjusted, the eraser can be used for a long period of time, and the eraser becomes very easy to use. In addition, since the knock cap is always urged in the backward direction and is held in a constant backward position when not knocking, the knock cap which has dropped when the eraser is advanced does not move along with the eraser,
The effect is that the movement can be reliably prevented.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a lock-type mechanical pencil according to an embodiment of this invention, Figure 2 is a plan view of the connector, Figure 3 is a left end view of Figure 2, and Figure 4 is the right end of Figure 2. 5 is a sectional view taken along the - line in Fig. 2, Fig. 6 is a sectional view taken along the - line in Fig. 1, Fig. 7 is a sectional view taken along the - line in Fig. 1, and Fig. 8 is a sectional view taken along the - line in Fig. −
A line sectional view, FIG. 9 is a - line sectional view of FIG. 1,
Fig. 10 is a sectional view of the rear cap, Fig. 11 is a sectional view taken along line A-A in Fig. 10, Fig. 12 is a sectional view taken along line B-B in Fig. 10, and Fig. 13 is a sectional view of the eraser holder. , FIG. 14 is a sectional view taken along the line CC in FIG.
Figure 5 is a sectional view showing another embodiment of the eraser holder;
16 is a cross-sectional view taken along the line D--D in FIG. 15, FIG. 17 is a cross-sectional view of the knob cap, and FIG. 18 is a cross-sectional view showing another embodiment of the eraser holder. In the figure, 1 is an outer cylinder, 4 is a core pipe, 7 is a rear cap, 8 is a connector, 9 is a feed screw member, 11 is an eraser holder, 12 is a knock cap, 13 is an eraser, 32 is a lead chuck, 3
5 is an elastic body for chuck tightening, 90 is a screw shaft portion, a
is the distance and S is the center.

Claims (1)

[Scope of utility model registration request] By pushing the lead chuck 32 toward the distal end in the axial direction, the core S stored inside is pushed out toward the distal end via the lead chuck 32.The core pipe 4 is made freely movable in the axial direction. The stored outer cylinder 1, a chuck tightening elastic body 35 that urges the core pipe 4 rearward and tightens the lead chuck 32, and a rear cap rotatably connected to the rear end side of the outer cylinder 1. 7, a knock cap 12 which is provided in the rear cap 7 so as to be movable in the axial direction while being restricted from moving in the axial direction, and whose rear end protrudes from the rear end of the rear cap 7; The eraser 13 is provided within the eraser 12 so as to be movable in the axial direction with movement in the axial direction being restricted.
It has an eraser holder 11 that holds the eraser holder 11, and a screw shaft part 90 that is inserted into the eraser holder 11 from the distal end side and moves the eraser holder 11 in the axial direction, and the distal end side of the screw shaft part 90 is The outer cylinder 1 is connected to the rear end side of the outer cylinder 1 so as to be movable in the axial direction with its movement in the axial direction being restricted, and the distance a between the rear end of the core pipe 4 and the tip of the threaded shaft portion 90 is defined. The feed screw member 9 is provided to create play, and the feed screw member 9 is urged backward to come into contact with the tip of the knock cap 12, so that when not knocking, the rear end of the core pipe 4 and the screw The rear end of the rear cap 7 is provided with a clip insertion groove 7c that communicates with the interior of the rear cap 7. An insertion piece 15a bent at the base of the clip 15 is press-fitted into the groove 7c, and a locking piece 15 bent at the tip of the insertion piece 15a is press-fitted into the groove 7c.
A writing instrument characterized in that the backward movement of the knob cap 12 is restricted by b.